Welcome to Demon School! Iruma-Kun: I Try My Best Every Day

Whenever people ask how he met Yila, Kalugya’s expression turns very strange. The whole situation was just too awkward at the time.

...Why on earth did I do something like that back then? (The author is really going all out.) But as for Yila, that demon...

She’s strong, at least stronger than him. And she’s clever, too, since she’s second in rank. Though in some ways, she’s surprisingly naive.

She’ll casually drag all of them into making promises like “Let’s be companions forever”...

So she’s a real handful, but she’s pretty dependable as a companion.